Properties of Refractories after Exposure to High Pressure Gases II

The chemical resistance of commercial and experimental cementbonded castables and phosphatebonded ramming mixes to an atmosphere of CO, CO2, H2, H2O, CH4 and H2S at 6.9 MPa (1000 psia) and 231, 371, and 538 °C was evaluated from their physical and mechanical properties and by XRD and DTA/TGA after exposure. The major changes in properties occurred during the first ten days and then generally remained constant up to the maximum exposure of sixty days. Cementbonded castables exposed to saturated atmospheres showed a significant increase in flexural strength and decrease in porosity which corresponded to the formation of boehmite, AlO(OH). The dissolution of CaO and P2O5 from the cement and phosphate bond phases, respectively, occurred in saturated atmospheres, but the dissolution of CaO had no major effect upon the flexural strength. Phosphatebonded refractories became weaker after exposure to saturated atmospheres. All of the refractories were structurally intact after the 60 day exposure